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Given the following partial dp array after processing some elements of arr, where dp[w] indicates if sum w is achievable: Index: 0 1 2 3 4 5 6 7 8 9 10 Value: T F T F T F F F F F F If total_sum = 10, which of the following could be the original input array?

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Dynamic Programming: Knapsack - Minimum Subset Sum Difference
Given the following partial dp array after processing some elements of arr, where dp[w] indicates if sum w is achievable: Index: 0 1 2 3 4 5 6 7 8 9 10 Value: T F T F T F F F F F F If total_sum = 10, which of the following could be the original input array?
A[2, 4, 6]
B[1, 2, 3]
C[5, 5]
D[1, 3, 4]
Step-by-Step Solution
Solution:
  1. Step 1: Analyze achievable sums

    dp shows sums 0,2,4 achievable (T), others false.
  2. Step 2: Check which array can produce these sums

    [2,4,6] can produce sums 0,2,4 by choosing 2 or 4 alone or none.
  3. Step 3: Verify other options

    [1,3,4] can produce sum 1,3,4 which is not reflected; [5,5] only 0,5,10; [1,2,3] produces sums 1,2,3, etc.
  4. Final Answer:

    Option A -> Option A
  5. Quick Check:

    dp matches sums achievable by [2,4,6] subset [OK]
Quick Trick: Check achievable sums against subset sums of candidate arrays [OK]
Common Mistakes:
MISTAKES
  • Ignoring sums not achievable
  • Assuming all sums possible
Trap Explanation:
PITFALL
  • Candidates pick arrays with sums close but not matching dp achievable sums.
Interviewer Note:
CONTEXT
  • Tests deep understanding of dp state and subset sums.
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